On my site, Schvenn.net I've recommended the use of Host Files for years. Today, I thought I'd reinforce that idea with some visuals to support my assertions.
The idea came to me when I was at work and I had to sit at a shared computer that I do not normally use. While I had some downtime I checked out one of my favourite sites, http://www.ListVerse.com and was thoroughly surprised when I got there. I barely recognized the site. There were ads all over the place, making it nearly unrecognizable. I quickly closed my browser, installed a host file and reopened it. The site returned to it's familiar appearance, now that the ads were blocked.
I've been using host files for so long that I take them for granted. In fact, if I forget to update the Host file on my PC from time to time, it won't matter too much, because I actually have the host file installed on my router, using a script in DD-WRT to update it every week. The benefit of this, is that every device in my home, on my network, is protected right from the router. So, no add-ons or plugins are needed to accomplish this task. No memory or processing power is taken up by additional software on each device, because the offending sites are blocked before they ever get inside my network.
Let me demonstrate the difference with a couple images. In order to accomplish this, I actually had to employ an outside source (www.BrowserShots.org) in order to get a view of what the site looks like to anyone without a host file installed. Otherwise, I would have to remove my host file and disconnect my router to accomplish the same task.
Next, I took an image of the site from my own computer, in order to present the comparison below and while the ads may not seem overly obtrusive in this screen capture below, let me assure you they are. For one thing, the system at work actually showed an additional and very large ad right below the first one I have marked below. All the ads are animated flash banners and as such, are very distracting. When you compare those to the view I normally see of the site, you can see a dramatic difference between the viewing experiences.
In addition to providing a better browsing experience, host files can also block malicious sites and known malware sources. So, there are additional reasons to use them.Now, take a look at the images below.